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Full text of "The Morphology And Evolution Of The Apes And Man"

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k                                    TABSIOIDBA                                29
Mascarene  Lemurs, which have the  full complement (see page 17).    Carpal vibrissae are absent.
Hair Slope.—Tarsius differs from the Lemurs as follows : (1) The hairs on the head are directed forwards ; (2) the hairs on the back diverge from the middle line; (3) the hairs on the forelimb all slope towards the rnanus; (4) there are spirals in the pectoral region but none on the abdomen.
Peculiar Glands.—These structures are absent. The nipples are four in number—two pectoral and two inguinal as in the Lorises and Galagos.
It is, therefore, evident that as regards the external characters the Lorises, Galagos and Tarsius have several points in common in which they differ from the Mascarene Lemurs.
Skull.—When viewed from the front the skull appears pyriform, with the narrow mandible below (fig. 11); and the broad upper part is formed mainly by the greatly expanded orbits. The latter are shut off from the temporal fossae by post-orbital walls; and only a thin partition separates them from one another. The upper orifice of the naso-lachrymal duct lies on the face outside the orbit as in the Lemurs, both living and extinct.
The alisphenoid meets the parietal bone in the pterion as in the Lemurs and many higher Primates, and the former helps to complete the orbital wall.
The glenoid fossa is slightly deeper than in the Lemurs, and, as in them, there is a post-glenoid process. The tympanic bullae are large, and there is a short, bony, external, auditory meatus. The internal carotid artery enters the skull through a foramen on the ventral surface of the bulla.